1. Field of the Invention
The present invention relates to the field of measurement of a test specimen for detecting a substance in the test specimen qualitatively or quantitatively.
2. Related Background Art
As a method for detecting in a test specimen so-called immunoactive substance such as an antigen or an antibody which is specifically bound to a specified antibody or antigen, there is known a method in which the immunoactive substance is sensitized to carrier particles (latex particles, glass particles, ceramic particles, kaolin, carbon black, colloidal particles such as erthrocytes and other animal blood components, and the like), and the carrier particles are reacted with a test specimen in a liquid medium, and the aggregating state of the carrier particles in the reaction solution is observed and verified with the naked eye , thereby detecting qualitatively the substance which is specifically bound to the sensitized substance. Also, for a quantitative detection, there is known a method in which an immunoactive substance is detected quantitatively in such a manner that the reaction solution is injected into a transparent test container and white light or the like is radiated thereto to measure the intensity fluctuations of the transmitting light, the scattering rays of light, and others.
However, with the above-mentioned conventional methods, it is difficult to maintain reproducibility while making the aggregating conditions constant. Moreover, when the aggregating state is determined with the naked eye, the detection tends to lack its quantitativeness. As a result, the test results are less accurate and reliable. Also, since a mechanical vibration should be given to the reaction solution in order to accelerate its aggregation, the mechanism of apparatus becomes large and complicated. In addition, although the method for performing a quantitative detection through the measurement of the transmitting light, scattered light and the like contributes to an improved quantitative accuracy, there is a problem that it takes a longer time to complete the test because the aggregating state must be measured twice or more after the reaction.